Add Q_OS_OSX and update the documentation to reflect usage intent.

Change-Id: I7f089109d7357995b65f6a012f705a6c3cac12ff
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@digia.com>
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>
XCB: Fix warning about unhandled enumeration values.

Introduced by 438211ec627073817fcaf6d3a07b76f2aa5d90e0 .

Change-Id: Ia6765c2a49f13958c70f83ebf79fdaadfdd25ac9
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>
Add WACOM tablet support for Windows.

Task-number: QTBUG-30008

Change-Id: I3327baecae7c5d1411bcd125411097f36460cde5
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>